I'm a simple guy, so my apps are kind of simple:
I like to read old comic strips, so I have the following apps:
Calvin & Hobbes
Dilbert
Boondocks
DailyStrip (which has hundreds of comics, but I just use it to read Foxtrot).
Even though Calvin & Hobbes and Boondocks aren't written anymore, they all update daily and they re-run old ones in order, so it's still pretty cool and gives me a good chuckle every morning when I check them.
I don't know how things work for you over there in ACF land, but the most useful apps I use are:
Barcode Scanner: (there's several of these, just scan a barcode of a product at a store, and it tells you the price and if another store close by has it cheaper somewhere else).
Flixster: best movie app I've used (and I've tried a few). Tells you what theaters are close by, what's playing at what theater, what's coming out soon, what's coming out on DVD etc.
Now the rest of the apps I use are games, which I tend to rotate out (but the games I play are pretty simple):
DroidEmuLite - let's you download old Nintendo, SNES, Genesis, Gameboy, etc. games. (I use a different app called Rom Buddy to download the games).
Connect4 - if you want to get your butt whooped at Connect4 download this and I'll be more than happy to whoop you
WordFeud - if you like scrabble this one is to have, seems like a large online community and you can play several games at once (because since you play on your phone you have like 24 or 48 hours to move, so it's good to have a few games going at once).
TrafficJam - a good puzzle solving game (you rearrange traffic to get your car out of the lot, get's pretty hard).
Abduction! and the Papi series of games (PapiJump, PapiRiver, PapiCatch, PapiPole, etc.) basically just move your phone to play the game, very simple but very fun.
That's about it for me. Those are the main ones I find fun and useful, but I'm a simple guy.